Résistance aux antimicrobiens

Fishery and aquaculture

What is the problem

Aquaculture is the globe’s fastest growing food production sector, and like other animal-rearing systems -- e.g. poultry, cattle, sheep -- disease represents an important impediment to production that must be dealt with. However, for aquatic animals (including fish, shellfish, shrimp and others), matters are more complicated, as there are over 500 such species that are farmed commercially -- and many affected by specific that target only them.

Fish are the most traded food commodity in international trade with an export value of nearly USD150 billion. This globalization of aquatic animal products and the rise of aquaculture as a primary supplier of the world’s aquatic food supply have been associated with the culture of new aquatic species, the movement of aquatic organisms to new countries and continents, and a general trend towards the intensification of production methods and the industrialization of the sector.

While this has created new market opportunities for farmed aquatic animals, it has simultaneously facilitated the spread of their pathogens and diseases. These trends have all led towards the increased reliance on veterinary medicines to ensure successful production through prevention and treatment of diseases, assuring healthy stocks and maximizing production.

Diseases are a primary constraint to the culture of many aquatic species and as a result, there is widespread use of anti-microbial veterinary medicines in aquaculture across the globe. Imprudent use of these veterinary medicines in aquaculture is a contributing factor in the spread of anti-microbial resistance. 

Challenges and solutions

Although the capability to manage aquaculture health issues has increased tremendously in the last 30 years, the rapid development of the aquaculture sector continues to generate new challenges. This is particularly apparent with increased interest in species diversification and new growing techniques. In addition to the impact on rural communities from large-scale fish losses due to disease, diseases also have considerable impact on investor confidence.

There are many factors contributing to the disease challenge including:

  • increased globalization of trade and markets;
  • intensification of fish-farming practices;
  • introduction of new species for aquaculture;
  • expansion of the ornamental fish trade;
  •  unanticipated interactions between cultured and wild populations of aquatic animals;
  • poor or lack of effective biosecurity measures;
  • slow awareness on emerging diseases;
  • irresponsible use of veterinary drugs; and
  • climate change.

One of the main solutions to control disease in aquaculture, as with other animal species, is the prudent use of veterinary medicines. It is recognised internationally that the use of medicines is important in disease control. The World Health Organization (WHO) has stated that “Antimicrobials are vital medicines for the treatment of bacterial infections in both human and animals”. Animal rearing needs the availability of effective antimicrobials to increase population survival rates, reduce chronic problems from infections and improve food conversion rates-- all of which impact production.

Careful use of veterinary medicines by fish farmers, improved regulatory frameworks, better enforcement of existing regulations by governments and improved health extension and diagnostic support services to the farmers would result in a more prudent and responsible use of veterinary medicines in aquaculture and contribute to a reduced threat of AMR .

However, antimicrobials should only be used after careful consideration of the options for disease prevention and control. Here, good aquaculture practices are key, as they lower disease risks and prevent disease, reducing the need for antibiotics and antimicrobials. Additionally, vaccinations can be used in aquaculture, again preventing diseases and reducing the need to rely on antibiotics and antimicrobials. The therapeutic use of bacteriophages to combat bacterial infections is being increasingly explored in aquaculture as an alternative to traditional antibiotics – as are probiotics and the immunostumlants. And where fish farming has led to waste contamination and prompted farmers to use antibiotics to cope, bioremediation – the use  of using living organisms (bacteria, fungi, actinomycetes, cyanobacteria and to a lesser extent, plants) to reduce pollutants is an alternative approach, as well.

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